From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42D8CC1B08C for ; Thu, 15 Jul 2021 05:00:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2AF9061374 for ; Thu, 15 Jul 2021 05:00:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236494AbhGOFDi (ORCPT ); Thu, 15 Jul 2021 01:03:38 -0400 Received: from smtp-out2.suse.de ([195.135.220.29]:55930 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236506AbhGOFDi (ORCPT ); Thu, 15 Jul 2021 01:03:38 -0400 Received: from imap1.suse-dmz.suse.de (imap1.suse-dmz.suse.de [192.168.254.73]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id D35EE1FDDB; Thu, 15 Jul 2021 05:00:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1626325240; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=anBNRoYQFt3DcretCgK2o1I04NRrV44A6TS6MWin4F4=; b=F40scGcn1PV8MO0zoRvUmtaWBHQty8jPKiDGXjaN6NdDuRgcLoed+arBOt7Ql2HTtZkQ3R EOm6dTmcEL2OLaKfKEuQyZlnpBVqLWOMieA5sSf6p8Ss4n6keidU+Y6oCp4a8Hp5b3X4sy aMD/46//U4Kcn2bAOqUZMcxc7qtYE+o= Received: from imap1.suse-dmz.suse.de (imap1.suse-dmz.suse.de [192.168.254.73]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap1.suse-dmz.suse.de (Postfix) with ESMTPS id 9201113AA4; Thu, 15 Jul 2021 05:00:39 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap1.suse-dmz.suse.de with ESMTPSA id qYd3FPfA72BBMgAAGKfGzw (envelope-from ); Thu, 15 Jul 2021 05:00:39 +0000 From: Qu Wenruo To: linux-btrfs@vger.kernel.org Cc: Qu Wenruo , Zhenyu Wu Subject: [PATCH v3] btrfs: rescue: allow ibadroots to skip bad extent tree when reading block group items Date: Thu, 15 Jul 2021 13:00:36 +0800 Message-Id: <20210715050036.30369-1-wqu@suse.com> X-Mailer: git-send-email 2.32.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org When extent tree gets corrupted, normally it's not extent tree root, but one toasted tree leaf/node. In that case, rescue=ibadroots mount option won't help as it can only handle the extent tree root corruption. This patch will enhance the behavior by: - Allow fill_dummy_bgs() to ignore -EEXIST error This means we may have some block group items read from disk, but then hit some error halfway. - Fallback to fill_dummy_bgs() if any error gets hit in btrfs_read_block_groups() Of course, this still needs rescue=ibadroots mount option. With that, rescue=ibadroots can handle extent tree corruption more gracefully and allow a better recover chance. Reported-by: Zhenyu Wu Link: https://www.spinics.net/lists/linux-btrfs/msg114424.html Signed-off-by: Qu Wenruo --- Changelog: v2: - Don't try to fill with dummy block groups when we hit ENOMEM v3: - Remove a dead condition The empty fs_info->extent_root case has already been handled. --- fs/btrfs/block-group.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c index 5bd76a45037e..9bc68515bc4a 100644 --- a/fs/btrfs/block-group.c +++ b/fs/btrfs/block-group.c @@ -2105,11 +2105,16 @@ static int fill_dummy_bgs(struct btrfs_fs_info *fs_info) bg->used = em->len; bg->flags = map->type; ret = btrfs_add_block_group_cache(fs_info, bg); - if (ret) { + /* + * We may have some block groups filled already, thus ignore + * the -EEXIST error. + */ + if (ret && ret != -EEXIST) { btrfs_remove_free_space_cache(bg); btrfs_put_block_group(bg); break; } + ret = 0; btrfs_update_space_info(fs_info, bg->flags, em->len, em->len, 0, 0, &space_info); bg->space_info = space_info; @@ -2212,6 +2217,14 @@ int btrfs_read_block_groups(struct btrfs_fs_info *info) ret = check_chunk_block_group_mappings(info); error: btrfs_free_path(path); + /* + * We hit some error reading the extent tree, and have rescue=ibadroots + * mount option. + * Try to fill using dummy block groups so that the user can continue + * to mount and grab their data. + */ + if (ret && btrfs_test_opt(info, IGNOREBADROOTS)) + ret = fill_dummy_bgs(info); return ret; } -- 2.32.0